?Geranium molle?

I think its Herb Robert, a quickly spreading weed in my garden, which has a horrid smell (like foxes) to me although others on this site quite like it!

I think Herb Robert too, leaves rather too divided for molle? Anyway its a wild geranium (cranesbill).
Whether its a weed or not depends on whether you want it and where its growing. Its very pretty, hardy, good tempered Ieven grows under a privet hedge) and an enthusiastic self seeder, a native of hedgerows and woodland. If you don't want it don't let it go to seed.

Herb Robert, well-behaved weed. Easy to pull out, fabulous red autumn leaves, semi-evergreen, there are white-flowered forms too.

Now I reckon it is not divided or red enough in the leaf for G. robertianum

And the flowers seem a little big for herb Robert. Could it be one of the woodland cranesbills ?

Wait until it sets seed then. the Herb Robert seed is straight and the woodland one is twisted.

Hey thanks all, I've looked up herb Robert and would agree that's what they are. They're so pretty. I've not noticed a smell though. Maybe I'm immune to the pong as we have so many foxes. There are some red leaves too already.

I have loads of these in the garden, mainly because I let them seed and they love to do that! Where they fill a space they can stay, if they encroach on anything else, they go, but they are pretty and the leaves and stems are colourful too. Easy to get rid of, so if it's not in the way I'd leave it.

You only notice the pong when you pull them up!

Herb Robert. Also known in my area as the headache flower due to its pungent smell as it can set off migraine if you are sussceptible.